TY - Generic T1 - Forest Disturbance and the Impacts on Maritime Snow in the Oregon Cascades T2 - 87th Annual Western Snow Conference Y1 - 2019 A1 - Mikey Johnson A1 - Anne Nolin KW - climate change KW - forest fires KW - maritime snowpacks KW - McKenzie River Basin AB -

The maritime mountain snowpack in Oregon’s Cascades is a critically important source of flows for the Willamette River Basin. Recent warm winters have reduced snowpack due to precipitation falling as rain rather than snow. Furthermore, landscape-altering forest fires have altered the energy balance, affecting snowpack retention. This research investigates changes in snow water equivalent (SWE) due to warmer climate and fires in the McKenzie River Basin. The McKenzie River supplies water and hydropower to the city of Eugene Oregon and is a key tributary of the Willamette River. In 2003 the B&B Complex Fire (367 km2) burned through Santiam Pass, at the headwaters of the MRB, severely burning the forest surrounding the Hogg Pass SNOTEL site. For this study, data were acquired from multiple SNOTEL and meteorological sites for the 20 years before and 15 years after the fire. We examined pre- and post-fire differences in SWE at the Hogg Pass SNOTEL site, in comparison with the nearby and unburned McKenzie SNOTEL site. We also modeled the changes in SWE, calibrating the model to the unchanged McKenzie SNOTEL and rerunning the model with a clear-cut forest cover to simulate disturbance. Next, we tested this model at the Hogg Pass SNOTEL for the years of pre- and post-fire. Results show that the measured SWE at the Hogg Pass SNOTEL it noticeably less in the years following the fire. Results from the modeled disturbance overestimate SWE at all times during the post-fire 2004 water year. From this, we conclude that the model’s landcover doesn’t fully represent the impacts on the snowpack following a forest fire. Further model development is needed to include these processes. This study is particularly relevant to water resource and forest managers who seek to understand how the declining seasonal snowpack will affect water availability and could increase the likelihood of more forest fires during the dry months.

JF - 87th Annual Western Snow Conference CY - Reno, NV UR - /files/PDFs/2019Johnson.pdf ER - TY - Generic T1 - A Proposal for a Change in Winter Snowpack Suspension Criteria Used in the Conduct of Cloud Seeding Programs in Utah T2 - 86th Annual Western Snow Conference Y1 - 2018 A1 - Randall Julander A1 - Jordan Clayton A1 - Don Griffith A1 - Candice Hasenyager AB -

Cloud seeding has long been recognized as a method of precipitation augmentation. In any given year, natural precipitation may range from exceptionally low to record highs. Clearly augmentation at low and average accumulations produces substantial water supply benefits and is the primary purpose for cloud seeding – to increase water supply. However, there needs to be clear criteria by which, in high accumulation years, cloud seeding is to be suspended due to the potential for snowmelt flooding. Years that have high snowpacks also have the highest potential for longer term, sustained high streamflow and flooding, years with lower snowpacks can and do produce flood events but normally require more extraordinary climatological phenomena to produce flooding and thus lower overall potential. As there are many and sundry causes for flooding and to be clear, the flood potential to be mitigated by snowpack cloud seeding suspension is specifically springtime snowmelt flooding/runoff. Other suspension criteria are used in the conduct of the Utah cloud seeding programs (e.g. no seeding during storms with high freezing levels that could produce winter flood events). Various other flooding mechanisms such as rain on frozen soil, urban flooding from impervious surfaces, flooding resulting from channel blockages, etc. would not be impacted by or mitigated by snowpack suspension criteria.

To address the snowmelt flooding issue, streamflow points were selected that were either unimpaired or minimized upstream management. The USDA Natural Resources Conservation Service SNOTEL stations were generally selected based on high elevation and geographic location relevant to the watershed being investigated. An attempt to correlate Snow Water Equivalent (SWE) index values to observed historical flood events was largely unsuccessful. The 95th percentile or approximately the 20-year recurrence interval was used for the index suspension criteria because it assures a robust water supply for the water year and yet is low enough to reduce flood potential as many municipalities utilize the 100-year recurrence for storm water design. (KEYWORDS: cloud seeding, SNOTEL, water supply, Utah, suspension criteria)

JF - 86th Annual Western Snow Conference CY - Albuquerque, New Mexico UR - /files/PDFs/2018Julander.pdf ER - TY - Generic T1 - Toward a Greater Understanding of Snowmelt Hydrology in Utah T2 - 85th Annual Western Snow Conference Y1 - 2017 A1 - Randall P. Julander A1 - Jordan Clayton AB -

Visual inspection of annual hydrographs from most rivers in the western U.S. supports the notion that
snowmelt provides the majority of streamflow in these areas. In Utah, the snowmelt period of April-July provides
an average of 71% of annual streamflow with 29% coming in the remaining 8 months, begging the question: what
proportion of streamflow comes from snowmelt? Previous estimates have been rough and have ranged from 60% to
80% or so; uncertainty stems from complexities such as rain on snow events, the geographic and temporal
distribution of precipitation events, and the partitioning of rainfall/snowmelt into streamflow. However, the
quantification of streamflow derived from summer precipitation is fairly simple on streams that have no upstream
regulation. It can be reasonably assumed that any rise in flow with a corresponding storm event is due to
precipitation, and the event flow can be separated from the base flow component of the hydrograph. We find that the
contribution of summer-month precipitation to annual streamflow in Utah is extraordinarily low: typically 1% to
2%. Using soil moisture and well depth data we also demonstrate that vast areas of Utah watersheds are incapable of
producing event flow from summer precipitation due to consumptive losses from evapotranspiration and other
factors. We use these data to infer that 98% to 99% of streamflow in Utah watersheds originates from melting snow
and associated processes. This analysis is likely representative of areas within other western states that have cool
continental climates, abundant snowfall, long-duration snowpacks (meaning that substantial portions of the
snowpack do not typically melt during the winter), and sedimentary bedrock, such as eastern Nevada, western
Colorado, portions of Idaho and Montana, and elsewhere. (KEYWORDS: snowmelt, streamflow, Utah, soil
moisture, SNOTEL)

JF - 85th Annual Western Snow Conference CY - Boise, Idaho UR - /files/PDFs/2017Julander.pdf ER - TY - Generic T1 - Hydrograph Characteristics in Relation to Low, Normal, and High Snowpacks in Utah – A Water Management Tool T2 - 84th Annual Western Snow Conference Y1 - 2016 A1 - Randall Julander AB -

Long term (>30 year) daily snow water equivalent (SWE) observations enable researchers to establish relationships between various SWE and hydrograph characteristics. The shape and magnitude of snowmelt hydrographs in Utah depend predominantly on the magnitude of the snowpack being melted.  As observed, years with low snowpacks melt out earlier, have lower peak flows and lower total flow volume than average or high snowpack years, and vice versa for high snowpack years.  However, in relation to melt-out dates at SNOTEL sites, a higher proportion of the annual April-July flow in low years is shifted toward the end of the hydrograph, whereas a larger proportion of flow occurs prior to melt-out in higher snowpack years. This paper examines the timing of peak flow and the proportion and distribution of flow relative to the timing of snowpack melt out at selected watersheds and SNOTEL stations across the state of Utah. The ability to predict the temporal distribution of streamflow based only on the magnitude of snowpack and the melt out date at specific SNOTEL sites could improve water management, especially where limited or no seasonal water supply forecasts are available. (KEYWORDS:  SNOTEL, Snow Survey, SWE, hydrograph, peak flow)

JF - 84th Annual Western Snow Conference CY - Seattle, Washington UR - /files/PDFs/2016Julander.pdf ER - TY - Generic T1 - Water Availability Index T2 - 80th Annual Western Snow Conference Y1 - 2012 A1 - Julander, Randall P. JF - 80th Annual Western Snow Conference PB - Western Snow Conference CY - Anchorage, Alaska UR - sites/westernsnowconference.org/PDFs/2012Julander.pdf ER - TY - Generic T1 - The Mill Flat Fire Hydrologic and Flood Potential Evaluation T2 - 79th Annual Western Snow Conference Y1 - 2011 A1 - Julander, R. A1 - Vaughn, K.S. A1 - Bricco, M. A1 - Uriona, B. A1 - Nault, B. KW - SNOTEL, NRCS, Utah, fire, flood, watershed evaluation, infiltration, soil moisture AB - The Mill Flat Fire near New Harmony in southern Utah in 2009 posed a substantial risk of flooding and possibly mud/debris flow from the steep terrain and nearly 200% of average snowpack in the area. This hydrologic evaluation and aerial photographic survey by NRCS Snow Survey quantified in general terms what that risk was based on the snowpack inside the fire area and on the contributing watershed versus outside the area where NRCS has a SNOTEL monitoring station. The assessment included the area's ability to infiltrate both snowmelt and a potential rain-on-snow event based on current soil moisture characteristics as well as measured infiltration rates. We were able to define at each sample location the current snowpack, soil moisture content, and an estimate of infiltration rates and to relate this information to the same information at the SNOTEL site. Large portions of the steep south facing aspects throughout the watershed, up to as high as 2590 meters in Dam Canyon, were bare of snow cover at the time of the survey even though snowpacks were much above average. However, areas that had even moderate slopes as low as 2255 meters on south east, east, north or northwest facing aspects still had substantial snowpacks. Data and analyses from the fire area indicated that the watershed could easily infiltrate much if not all of the snowpack and that the greatest danger of flooding would be a large rain-on-snow event. JF - 79th Annual Western Snow Conference T3 - Proceedings of the 79th Annual Western Snow Conference PB - Western Snow Conference CY - Stateline, NV UR - sites/westernsnowconference.org/PDFs/2011Julander.pdf ER - TY - Generic T1 - Assessing the Sensitivity of Wasatch Mountain Snowfall to Temperature Variations T2 - 77th Annual Western Snow Conference Y1 - 2009 A1 - Jones, L.P. A1 - Horel, J.D. KW - Wasatch Mountains, climate change, snow sensitivity, SNOTEL AB - Three methods are employed in this study to estimate the sensitivity of snow falling in the Wasatch Mountains of northern Utah to observed and projected changes in atmospheric temperature. Daily precipitation data from 1 October to 30 April 1979-2008 are examined from selected snowpack telemetry (SNOTEL) sites in northern Utah. Profiles of wet bulb temperature from near crest level (700 mb) to elevations along the mountain slopes of selected watersheds are estimated on days with precipitation soundings launched from the nearby Salt Lake City airport. The rain-snow line is assumed to correspond uniformly to the elevation of the wet bulb temperature equal to 1oC. Probability distribution functions of the fraction of precipitation falling as snow as a function of daily wet-bulb temperature are computed. The percentage of precipitation estimated to fall at wet-bulb temperatures in the range 0-1oC is assumed to switch from snow to rain if temperatures increase by 1oC. While the sensitivity to temperature depends strongly on elevation within the watershed, an increase in tropospheric temperatures of 1oC is estimated to lead to an 8-10% decrease in snow when averaged over the selected watersheds. JF - 77th Annual Western Snow Conference T3 - Proceedings of the 77th Annual Western Snow Conference PB - Western Snow Conference CY - Canmore, AB UR - sites/westernsnowconference.org/PDFs/2009Jones.pdf ER - TY - Generic T1 - Characteristics of Snow Water Equivalent to Precipitation Ratios in Utah T2 - 76th Annual Western Snow Conference Y1 - 2008 A1 - Julander, Randall P. A1 - Bricco, M. KW - SWE, precipitation, climate change, ratio, systematic bias AB - Snow water equivalent (SWE) to precipitation (PCP) ratios have recently been used as evidence to support climate change. The assumption is that when a site or region's SWE to PCP ratio declines, temperature is a driving mechanism. In fact, there is a reasonable linear statistical relation between these two variables, but there may be other influencing factors involved in both the site and regional SWE to PCP relations. There are distinctly different physical phenomena occurring at land surface relative to the location of the orifice of a precipitation gage some distance above that surface, such as vegetation and wind direction, run and general velocity. There also is a large 'scale' difference in exposed area of data collection between a 3.05 meter diameter snow pillow and a 30.5 cm diameter precipitation gage. SWE to PCP ratios change throughout the snow accumulation season and SWE, in general, outpaces precipitation accumulation. Therefore, a SWE to PCP ratio analysis on some arbitrary date such as April 1 may have strong systematic bias. The result is that the overall magnitude of SWE in any given year may be a strong indicator of the eventual SWE to PCP ratio. JF - 76th Annual Western Snow Conference T3 - Proceedings of the 76th Annual Western Snow Conference PB - Western Snow Conference CY - Hood River, OR UR - sites/westernsnowconference.org/PDFs/2008Julander.pdf ER - TY - Generic T1 - An Engineering Design Study of Electronic Snow Water Equivalent Sensor Performance T2 - 75th Annual Western Snow Conference Y1 - 2007 A1 - Johnson, G.B. A1 - Gelvin, A. A1 - Schaefer, G.L. KW - Snow sensor, SWE, CRREL, NRCS, Hogg Pass, freeboard AB - The USA ERDC CRREL and the USDA NRCS developed an electronic SWE sensor based on the results of field and theoretical studies of SWE pressure sensor performance. The CRREL/NRCS sensor is about 3 m square and is modular consisting of nine perforated panels, a center panel and eight outer surrounding panels that allow water to percolate through the sensor. Water percolation minimizes thermal differences between the sensor and surrounding soil and the eight surrounding panels act to buffer the center panel, where SWE is measured, from stress concentrations that develop along the perimeter of the sensor. Two years of field-tests (winters of 2005-2006 and 2006-2007) at Hogg Pass, OR, demonstrate that the CRREL/NRCS sensor's center panel accurately measures SWE variations even when stress concentrations are observed on the sensor's outer panels. During the first winter, stress concentrations occurred on the outer panels during periods of rapid snow settlement following large snow accumulations and when the rate of snowmelt at the sensor/snow interface was significantly different from the snowmelt rate at the soil/snow interface of the surrounding ground. SWE measurement performance is optimal when the sensor has no freeboard. JF - 75th Annual Western Snow Conference T3 - Proceedings of the 75th Annual Western Snow Conference PB - Western Snow Conference CY - Kailua-Kona, HI UR - sites/westernsnowconference.org/PDFs/2007Johnson.pdf ER - TY - Generic T1 - Soil Surface Temperature Difference Between Steel and Hypalon Pillows T2 - 75th Annual Western Snow Conference Y1 - 2007 A1 - Julander, Randall P. KW - SNOTEL, hypalon, stainless steel, snow accumulation, systematic bias AB - Systematic bias in data collection systems is often difficult to identify and moreover, on a site specific basis, hard to correct. Systematic bias in the SNOTEL record between steel and hypalon pillows has been identified and ranges between 0% and 25% (Julander and Bricco, 2006, Osterhuber, 1996). Observationally, the greater differences are typically at lower elevations and warmer temperatures while higher elevation, cooler sites typically have lower differences or none at all. Since originally the entire SNOTEL system was installed with steel pillow and since that time many steel pillows have been replaced with hypalon, it is essential to take a second look at these parameters to insure data consistency and accurate results. Hypalon pillows could become a heat sink, absorbing energy in the summer and slowly releasing it through later periods which could impact early season snow accumulation. The black pillows might possibly increase solar energy absorption during ablation, increasing melt rates in the spring. To test this hypothesis, temperature sensors were placed under co-located hypalon and steel pillows at Parleys Summit and Trial Lake SNOTEL sites in Utah. Results indicate that there is a substantial temperature difference and that it is possible that this difference could impact snow accumulation and ablation. JF - 75th Annual Western Snow Conference T3 - Proceedings of the 75th Annual Western Snow Conference PB - Western Snow Conference CY - Kailua-Kona, HI UR - sites/westernsnowconference.org/PDFs/2007Julander.pdf ER - TY - Generic T1 - Web-based Flood Chronology of the Carson River basin, California and Nevada, from 1852 to the Present T2 - 74th Annual Western Snow Conference Y1 - 2006 A1 - Jeton, A.E. KW - Floods, Nevada, floodplain mapping, FEMA, USGS, Carson River AB - As new areas are developed to accommodate growth, communities are increasingly faced with the need to develop in flood-prone areas. Current efforts by the State of Nevada Floodplain Management Program, Nevada Division of Water Resources (NDWR), to support the Federal Emergency Management Agency's (FEMA) Map Modernization program, have been to act as a point of contact at the State level in communicating mapping needs for Nevada communities. In conjunction with floodplain mapping, NDWR has identified the task of compiling flood-hazard information in a format accessible and understandable to the general public and Federal, State, regional, and local agencies. The Nevada Floodplain Management Program considers it essential to make historical flood information publicly available, particularly for river basins with significant current and future population growth. The U.S. Geological Survey with the support of FEMA through NDWR's Floodplain Management Program has developed a web site to make historic flood information for the Carson River Basin publicly available. The web site contains information to help the general public in understanding the extent and frequency of flood hazards and risks in the Carson River Basin. Available information on specific flood events may include photographs, video clips, and links to related web sites, flood-frequency analyses, meteorological data, narratives, and streamflow data. USGS Fact Sheet 2006-3102 provides additional information, and the URL for this web site is http://nevada.usgs.gov/crfld/. JF - 74th Annual Western Snow Conference T3 - Proceedings of the 74th Annual Western Snow Conference PB - Western Snow Conference CY - Las Cruces, NM UR - sites/westernsnowconference.org/PDFs/2006Jeton.pdf ER - TY - Generic T1 - An Examination of External Influences Embedded in the Historical Snow Course Data of Utah T2 - 74th Annual Western Snow Conference Y1 - 2006 A1 - Julander, Randall P. A1 - Bricco, M. AB -

Snowpack data collection has a long and storied history in Utah as well as the western United States. In Utah, records extend back to at least 1912. Systematic measurements began in the mid 1920's with many long-term snow courses established at that time. Each site was meticulously mapped, described and most important, photographed from several angles. Comparisons are made between the 1936 photographs, maps and descriptions and current conditions, specifically with regard to vegetation. General conclusions are made regarding the impact that vegetation change has had on snow accumulation at each course. With the advent of weather modification programs, changes in snow accumulation could reasonably be expected. Utah began a relatively small test weather modification program in the 1950's in central Utah. The Utah cloud seeding act was passed in 1973 and the seeding program has continued since that time. Snow Courses affected by this program are identified and the potential impact on historical data. The impact of sensor change from steel pillows to hypalon is discussed. Physical changes at data collection sites are estimated. Finally, recommendations for individual snow course suitability for long-term study based on consistency are made for each of the courses examined. SNOTEL sites, the automated version of the snow courses began to be installed in the late 1970's and early 1980's. These sites to a lesser degree due to the shorter historical time of data collection, have been impacted by vegetation change as well.

JF - 74th Annual Western Snow Conference T3 - Proceedings of the 74th Annual Western Snow Conference PB - Western Snow Conference CY - Las Cruces, NM UR - sites/westernsnowconference.org/PDFs/2006JulanderB.pdf ER - TY - Generic T1 - Floods, Droughts, and Extremes in Utah Snowpacks T2 - 74th Annual Western Snow Conference Y1 - 2006 A1 - Julander, Randall P. KW - Extremes, drought, tree rings, Colorado River, global warming, declining snowpack AB -

Utah has seen hydrometeorological extremes over the past decade. Last year saw snowpack records not just exceeded but shattered at some sites. In one case, snowpack was 50.8 centimeters higher than the previous record long term maximum snow water equivalent. This single year erased the total deficit of the six previous drought years at this site. Other sites had record snowpack in southern and northeastern Utah. Previously, six consecutive years of drought had decimated reservoir storage, caused huge forest and range mortality in even the hardy Atemesia species. Tree ring records indicate that this was one of the more significant droughts over the past 480 years in the Colorado River Basin (Woodhouse, 2003). The drought has caused significant agricultural damages as well as to other sectors of the economy such as power and tourism. The ever present concern over global warming and its impact on western snowpacks has been mentioned in numerous studies as well as through public discourse. Historical analysis has shown that at 15 carefully chosen, long term snow courses snowpacks have been on a gradual decline although none were statistically significant. This study quantifies the impacts of these extremes on snowpack averages at these 15 sites. Are these times really different than those of historical past and are they really more extreme?

JF - 74th Annual Western Snow Conference T3 - Proceedings of the 74th Annual Western Snow Conference PB - Western Snow Conference CY - Las Cruces, NM UR - sites/westernsnowconference.org/PDFs/2006JulanderA.pdf ER - TY - Generic T1 - An Analysis of the Timing of Snow Course Measurement and the Potential Error Compared to April 1 Measurement in Utah T2 - 73rd Annual Western Snow Conference Y1 - 2005 A1 - Julaner, R.P. KW - Utah, snowpack, snow survey, runoff forecasting, SNOTEL, climate change, SWE prediction, April 1 AB -

Snowpack data collection began in an organized fashion in Utah during the late 1920's. The April 1 measurement soon proved to be one of the most important surveys with regard to water supply forecasting. These snow survey data, used historically as April 1 data were seldom actual April 1 measurements rather they were normally sampled at some time prior to April 1, in the latter part of March. In the way that Snow Survey Data were being used, principally in linear regression applications versus accumulated streamflow, this presented little error in the forecasting scheme. However, with the advent of telemetered snowpack information, there exist now two sets of data - those manual sites still measured during the end of March and the SNOTEL or electronic data which are actual April 1 values. The snow course data would underestimate the actual April 1 snowpack compared to the SNOTEL data set, however the magnitude of the error has not been determined. Climate change is being characterized by impacts seen in snowpack. For this type of analysis, the longer the data set, typically the better and more substantial and conclusive the findings. SNOTEL has a relatively short record being installed in the late 70's and early 80's but the snow course data reach back into the 20's, making the analysis far more long term. SNOTEL replaced many of the long term snow courses, thus reducing the pool of available long term data for analysis. This analysis compares the potential error associated with actual measurement timing to April 1 and provides an average correction factor for adjusting long term snow course data to observed SNOTEL data in Utah.

JF - 73rd Annual Western Snow Conference T3 - Proceedings of the 73rd Annual Western Snow Conference PB - Western Snow Conference CY - Great Falls, MT UR - sites/westernsnowconference.org/PDFs/2005JulanderB.pdf ER - TY - Generic T1 - Soil Type and Site Location Impacts on Soil Moisture Data Collection at High-Elevation SNOTEL Sites T2 - 73rd Annual Western Snow Conference Y1 - 2005 A1 - Julaner, R.P. A1 - Holcombe, J. KW - NRCS, SNOTEL, soil moisture sensors, soil profile, topographic convergence, elevation AB -

The Natural Resources Conservation Service has recently begun the installation of soil moisture sensors at SNOTEL sites in the western United States in an effort to better characterize watershed hydrology pertaining to snowmelt runoff. Most research in the movement of water through a soil profile has been done in agricultural settings where topography is relatively flat, vegetation is relatively homogenous, and soils are typically fine textured and deep. This paper attempts to document some of the anomalies encountered in soil moisture data from mountainous sites and link them to potential site physical characteristics such as topographic convergence or divergence, distance to bedrock, and elevation, as well as soil type and texture.

JF - 73rd Annual Western Snow Conference T3 - Proceedings of the 73rd Annual Western Snow Conference PB - Western Snow Conference CY - Great Falls, MT UR - sites/westernsnowconference.org/PDFs/2005JulanderA.pdf ER - TY - Generic T1 - The influence of thermal, hydrologic, and snow deformation mechanisms on snow water equivalent pressure sensor accuracy T2 - 70th Annual Western Snow Conference Y1 - 2002 A1 - Johnson, J.B. A1 - Schaefer, G.L. KW - SWE, Pressure transducer error, Heat budget, Snow core AB - A five-year field study was conducted to determine the mechanisms that cause snow water equivalent (SWE) pressure sensor measurement errors. We monitored a 3-m snow pillow and installed three prototype electronic SWE sensors to examine how SWE errors occur. We measured heat flux in the sensors and the soil, snow temperature, soil moisture content, and soil thermal conductivity. The SWE of snow cores were used to assess the accuracy of the sensors. Results indicate that SWE measurement errors occur when the snow/SWE sensor and/or the snow/soil interfaces are at the melting temperature of snow. SWE over measurement errors occur when the sensor heat flux is less than the surrounding soil. SWE under measurement errors occur when the heat flux through the sensor is greater than through the soil. The most severe errors occur during the transition from winter to spring when the snow cover first reaches an isothermal condition producing a maximum difference in snowmelt rate between the snow/SWE sensor and snow/soil interfaces. SWE measurement errors are minimized when the sensor is designed to match the thermal properties of the surrounding soil, allow water to flow through the sensor, or to diffuse heat into the adjacent soil. JF - 70th Annual Western Snow Conference T3 - Proceedings of the 70th Annual Western Snow Conference PB - Western Snow Conference CY - Granby, Colorado UR - sites/westernsnowconference.org/PDFs/2002Johnson.pdf ER - TY - Generic T1 - A historical comparison of snowpack averages in Utah. T2 - 70th Annual Western Snow Conference Y1 - 2002 A1 - Julander, Randall P. A1 - Perkins, T. KW - SNOTEL, Utah snowpack, Telemetering, Snow courses AB -

Snowpack data collection began in an organized fashion in Utah during the late 1920's and the first 30-yearaverage was calculated in the late 1950's. Individual sites are used to calculate moving 30-year averages each yearin this continuous record up to current data. Snowpacks are analyzed over this time period by site, region andelevation to determine any significant changes. Snowpacks in southern areas are compared to those in northernUtah as well as low elevation sites to the higher elevations to ascertain potential trends or differences. SNOTEL isa telemetering system providing daily snow water equivalent, precipitation and temperature data. Installed in thelate 1970's and early 1980's, it provides accurate data on site specific melt out dates. SNOTEL provides far greaterdata than the manual snow course system does, but has a much shorter period of record, limiting it's statisticalrelevance. Given the statistical limitations of a 25 year period of record, snowpack melt-out dates are examinedstatewide to determine if there are definable trends.

JF - 70th Annual Western Snow Conference T3 - Proceedings of the 70th Annual Western Snow Conference PB - Western Snow Conference CY - Granby, Colorado UR - sites/westernsnowconference.org/PDFs/2002Julander.pdf ER - TY - Generic T1 - Soil moisture data collection and water supply forecasting: the sequel T2 - 70th Annual Western Snow Conference Y1 - 2002 A1 - Julander, Randall P. KW - SWE, Spatial interpolation, Snow depth, Binary regression tree AB -

The strong relationship between snow water equivalent and seasonal water supply has long since been demonstrated. Theses statistical relationships vary in strength depending on a host of factors such as latitude, elevation, and others. Part of the error associated with these relationships is due to unknown future meteorological conditions that impact the timing and volume of the runoff.  Another part of the error associated with statistical relationships is due to the variable state of soil moisture.  Soil moisture conditions across a watershed are generally presumed to influence seasonal water supplies from snowpack (Wetzel and Woodward, 1987).  If extremely dry conditions are prevalent in the fall prior to the seasonal snowpack, then it is presumed that these soils have additional capacity to absorb and retain some greater than normal amount of snowmelt, leaving a reduced amount to generate seasonal streamflow. Conversely, if the soils are saturated prior to the onset of snowmelt, it is presumed that, since the soils have less capacity for infiltration and certainly less storage, that the majority of snowmelt should contribute directly to seasonal streamflow.  The total potential snowmelt loss to soil moisture recharge can be significant, assuming a 24 inch soil depth, 8 to 10 inches of snowmelt or more, could be infiltrated depending on soil type and condition.  Some portion of this would eventually contribute to runoff and some portion would be lost from the immediate contributing system through either evapotranspiration or to deeper groundwater.  The Natural Resources Conservation Service now has soil moisture sensors at five sites in Utah (Julander and Cleary, 2001) with plans to install many more.  Preliminary data indicate great potential value from these data in reducing water supply forecast error. Interesting relationships between summer/fall precipitation and soil moisture are analyzed.  Snowpack, soil moisture and runoff are compared.

JF - 70th Annual Western Snow Conference T3 - Proceedings of the 70th Annual Western Snow Conference PB - Western Snow Conference CY - Granby, Colorado UR - sites/westernsnowconference.org/PDFs/2002Julander2.pdf ER - TY - Generic T1 - STREAMFLOW FORECASTING USING THE MODULAR MODELING SYSTEM AND AN OBJECT-USER INTERFACE T2 - 69th Annual Western Snow Conference Y1 - 2001 A1 - Jeton, A.E. KW - Data management, Simulation model AB -

The U.S. Geological Survey (USGS), in cooperation with the Bureau of Reclamation (BOR), developed a computer program to provide a general framework needed to couple disparate environmental resource models and to manage the necessary data. The Object-User Interface (OUI) is a map-based interface for models and modeling data. It provides a common interface to run hydrologic models and acquire, browse, organize, and select spatial and temporal data. One application is to assist river managers in utilizing streamflow forecasts generated with the Precipitation-Runoff Modeling System running in the Modular Modeling System (MMS), a distributed-parameter watershed model, and the National Weather Service Extended Streamflow Prediction (ESP) methodology.

JF - 69th Annual Western Snow Conference T3 - Proceedings of the 69th Annual Western Snow Conference PB - Western Snow Conference CY - Sun Valley, Idaho UR - sites/westernsnowconference.org/PDFs/2001Jeton.pdf ER - TY - Generic T1 - STREAMFLOW FORECASTING USING THE MODULAR MODELING SYSTEM AND AN OBJECT-USER INTERFACE T2 - 69th Annual Western Snow Conference Y1 - 2001 A1 - Julander, Randall P. A1 - Cleary, S. KW - Forecasting, Snowpack, Soil moisture AB -

Extreme deviations in hydroclimatic conditions are a source of considerable error in statistical water supply forecast models. Much attention has been given over the past years to the relationship between snowpack, precipitation and streamflow (Martinec, 1975, Hawley, et al. 1980, McCuen, 1993). These relationships tend to vary in strength, but in large part are satisfactory for water supply forecasting purposes. Many other hydroclimatic variables such as soil moisture are implicit in these statistical relationships. As long as these variables (soil moisture) remain proportional to the independent variables (snowpack, precipitation) in the forecasting relationship, then the model will be stable. If there is some amount of disproportion, then the model will most likely produce significant error. Such a case in northern Utah is presented along with an explanation of a small- scale implementation of soil moisture monitoring of two small watersheds in the Wasatch Mountains near Salt Lake City.

JF - 69th Annual Western Snow Conference T3 - Proceedings of the 69th Annual Western Snow Conference PB - Western Snow Conference CY - Sun Valley, Idaho UR - unavailable for now ER - TY - Generic T1 - The Franklin Basin problem T2 - 66th Annual Western Snow Conference Y1 - 1998 A1 - Julander, Randall P. A1 - Wilson, G.R. A1 - Nault, R. KW - Ice layer, Rain on snow, SNOTEL AB - The Franklin Basin SNOTEL site displayed very curious and conflicting data during the winter of 96-97. Pillow data were far too high and various means and tests were undertaken to determine the cause and extent. The more data gathered, the more confusing reality seemed to become. The eventualconclusion was that a combination of snow creep and additional water from rain on snow events which formed an ice layer on the pillow resulted in the pillow overweigh. JF - 66th Annual Western Snow Conference T3 - Proceedings of the 66th Annual Western Snow Conference PB - Western Snow Conference CY - Snowbird, Utah UR - sites/westernsnowconference.org/PDFs/1998Julander.pdf ER - TY - Generic T1 - Coal Lake outlet freeze-up, containment of winter inflows and estimates of telated outburst flood on Wolf Creek, Yukon Territory T2 - 65th Annual Western Snow Conference Y1 - 1997 A1 - Jasek, M. A1 - Ford, G. KW - Coal Lake, Spring freshet, Wolf Lake, Yukon River AB - Spring snowmelt is generally the dominant annual peak flow generating mechanism in subarctic regions, thoughsmaller basins may occasionally experience peak flow events due to summer rain storms. An unusual lake outburstflood event was observed at Wolf Creek, a small tributary of the Yukon River. The event was focused at the outletof Coal Lake the only major storage element in the basin.During the unusually cold January of 1996 ice growth at the outlet of Coal Lake created an ice dam which progressively grew through aufies formation as the lake levels increased. The ice dam failed in late April approximately 9 days after the onset of mean daily positive temperatures sending a significant flood wave downstream. This event was in excess of 1996 freshet flows which occurred more than one month later.There are three hydrometric stations on Wolf Creek however these were not activated until the recession of the outburst event. A water balance was carried out to reconstruct this flood event using observed lake levels for the containment period, the recorded recession limbs of hydrographs at the Coal Lake hydrometric station and a downstream hydrometric station, winter recession flows at an upstream hydrometric station and personal observation.The analyses indicated that the outburst event was greater in magnitude than the subsequent freshet event. In addition to facilitating the reconstruction of the annual hydrograph, the analyses provides valuable information on a little known strearnflow generation mechanism in small subarctic basins with lake storage. JF - 65th Annual Western Snow Conference T3 - Proceedings of the 65th Annual Western Snow Conference PB - Western Snow Conference CY - Banff, Alberta UR - sites/westernsnowconference.org/PDFs/1997Jasek.pdf ER - TY - Generic T1 - River basin variations in Sierra Nevada snowpack accumulation trends T2 - 65th Annual Western Snow Conference Y1 - 1997 A1 - Johnson, T. A1 - Dozier, J. A1 - Michaelsen, J. A1 - Fohl, P. KW - Climate change, Precipitation patterns, Statistical model AB - Mountainous areas, particularly in the western United States, provide a large fraction of the fresh water supply. This reserve, which supplies most of California's growing water needs, is vulnerable to changes in climate. Regional precipitation patterns, especially snow, which is a sensitive indicator of change, are predicted to vary according to future climate models. This study uses a statistical model which links snow water equivalent (SWE) measurements over a 6O-year time series to analyze the snow accumulation trends in the Sierra Nevada.We utilized snow course measurements with data difficulties including inconsistent monthly sampling, added and removed stations and possibly a few moved or otherwise altered snow courses. To determine the effects of a monthly and irregular sampling schedule we analyzed daily snow sensor data spanning 25 years. Furthermore, we employed a statistical test to check for possibly discontinuous snow course stations.We found that the overall maximum amount of seasonal SWE is not changing. However, below 2700 meters, snowmelt timing has recently been occurring earlier, whereas elevations above 2900 meters are melting later. The eastern draining river basins consist of steeper, drier slopes that have mostly increasing SWE trends. The Owens River basin, in the southeastern tip of the range, has gained the most SWE while the neighboring, westside Kern has received less snow. JF - 65th Annual Western Snow Conference T3 - Proceedings of the 65th Annual Western Snow Conference PB - Western Snow Conference CY - Banff, Alberta UR - sites/westernsnowconference.org/PDFs/1997Johnson.pdf ER - TY - Generic T1 - Tree rows for snow accumulation in stock ponds T2 - 63rd Annual Western Snow Conference Y1 - 1995 A1 - Jairell, R.L. A1 - Schmidt, R.A. KW - Living barriers, Scale models, Snow drifting, Snow fences AB - This paper presents results of small scale model experiments to determine optimum location of tree rows for increasing snowdrift volumes in pit reservoirs. These small scale model studies suggest that when a tree row is used to accumulate snow in a pit reservoir, the only effective location as at the upwind edge of the pit. Trees will draw water from the reservoir, reducing the volume available for other uses. However, amounts are of the same order as evaporation rates, and are likely to be less than seepage losses, unless the pit is lined. Low-use evergreen species reduce this water use to approximately half the amount required by cottonwood, poplar or willow. The benefits of vegetative barriers – as wildlife habitat, for example—may offset the difficulties of establishing and maintaining a living barrier. JF - 63rd Annual Western Snow Conference T3 - Proceedings of the 63rd Annual Western Snow Conference PB - Western Snow Conference CY - Sparks, Nevada UR - sites/westernsnowconference.org/PDFs/1995Jairell.pdf ER - TY - Generic T1 - Impact of climate change on water supply in the upper Yukon River T2 - 62nd Annual Western Snow Conference Y1 - 1994 A1 - Janowicz, J.R. A1 - Ford, G. KW - Climate change, Glacier, Model AB - A study was carried ot to determine the impact of projected climate change on water supply in the Yukon River above Whitehorse. The system is glacier fed with peak flows in late summer. Earlier low elevation snowmelt keeps water levels high for most of the summer. Historical monthly values of temperature and precipitation were used to develop a relationship with streamflow. Changes in temperature and precipitation based on a projected 100 percent increase in CO2 were used as a starting point to assess water supply impact. Evapotranspiration rates were estimated using a method which requires readily available parameters. These values were compared with projected monthly inflows to assess climate chamge impacts on the water balance. JF - 62nd Annual Western Snow Conference T3 - Proceedings of the 62nd Annual Western Snow Conference PB - Western Snow Conference CY - Sante Fe, New Mexico UR - sites/westernsnowconference.org/PDFs/1994Janowicz.pdf ER - TY - Generic T1 - The relationship of the annual snowpack to the water yield from the inner basin of the San Francisco Peaks, Arizona T2 - 61st Annual Western Snow Conference Y1 - 1993 A1 - Jones, R.A. KW - Forecast, SNOTEL, Statistical analysis AB -

During the period 1970-1991 the glaciofluvial deposits in the inner basin of the San Francisco Peaks, Arizona, have produced as much as 28% and as little as 2% of the annual water supply of the city of Flagstaff. This water is produced from wells and developed springs. Regression analysis indicates that water production shows a good correlation with maximum snow water equivalent, especially the production of the springs (r = 0.92). However, scheduled snow surveys may miss the maximum snow water equivalent measurement. The installation of a SNOTEL telemetry site would produce a daily record, thus insuring this maximum measurement. The SNOTEL data should contribute to the development of better water production forecasts.

JF - 61st Annual Western Snow Conference T3 - Proceedings of the 61st Annual Western Snow Conference PB - Western Snow Conference CY - Quebec City, Quebec UR - sites/westernsnowconference.org/PDFs/1993JonesA.pdf ER - TY - Generic T1 - Snow-atmosphere interactions in Arctic snowpacks -- net fluxes of NO3, SO4 and influence of solar radiation T2 - 61st Annual Western Snow Conference Y1 - 1993 A1 - Jones, H.G. A1 - Pomeroy, J.W. A1 - Marsh, P. A1 - Davies, T.D. A1 - Tranter, M. KW - Snowpack chemistry AB -

Identical experiments on snow-atmosphere interaction were carried out at two arctic sites (open forest and tundra, Inuvik, Canada) prior to spring snowmelt, April 1992. The purpose of the experiments was to estimate the magnitude and direction of net fluxes (dry deposition/re-emission) of NO3 and SO4 between the snow surface and the atmosphere from changes in concentrations of these species in the surface snow over periods of 36-48 hours. The experiment was also designed to determine the influence of solar radiation on fluxes of NO3 and SO4. The methodology included a procedure to homogenize surface snow; this served to normalize the initial chemical conditions for all sample sets used in the experiment. The homogeneous samples were exposed to the atmosphere in a series of mesh bags which allowed free exchange of water vapour, trace gases and aerosols between the atmosphere and the snow. The control study for the influence of solar radiation on the snow-atmosphere exchange was identical to that of the bagged snow under open sunny sky except that it was carried out in the shade of an opaque fly sheet. The chemical composition and snow-water equivalent (SWE) of all bagged snows were determined before and after each experiment. The results from experiments at both sites show that solar radiation had no influence on show-atmosphere exchange of NO3 and SO4. In the first experiment at the forested site sublimation of water vapour from the snow occurred. The mass loss of water vapour was equally offset in sun and shade by significant increases in NO3 concentrations and no net loss or gain of this species by snow-atmosphere exchange thus took place. Changes in the concentrations of SO4 were not significant indicating that no dry deposition of this species had occurred. In the second experiment at the tundra site there was no loss of mass by sublimation. However in this case a significant net exchange of SO4 from the atmosphere to the snow with a dry deposition velocity of 0.09 cm/s was measured.

JF - 61st Annual Western Snow Conference T3 - Proceedings of the 61st Annual Western Snow Conference PB - Western Snow Conference CY - Quebec City, Quebec UR - sites/westernsnowconference.org/PDFs/1993JonesB.pdf ER - TY - Generic T1 - Harvesting snow when water levels are low T2 - 60th Annual Western Snow Conference Y1 - 1992 A1 - Jairell, R.L. A1 - Schmidt, R.A. KW - Fence-pit-berm, High plains, Livestock water supply, Water source AB - Designing a snow fence-pit-berm water source for livestock of wildlife on the High Plains begins by estimating available snow transport, from average winter snowfall and fetch distance along the drifting wind direction. Pit excavation must match this volume of water. The pit will then trap one-half the snow transport. A snow fence height is chosen to provide storage for the one-half of snow transport not stored in the pit. The snow fence, pit, and berm are extended across the wind to match the water requirements (number of animals, number of days of use). Cost is less than most wells with pumping systems. JF - 60th Annual Western Snow Conference T3 - Proceedings of the 60th Annual Western Snow Conference PB - Western Snow Conference CY - Jackson Hole, Wyoming UR - sites/westernsnowconference.org/PDFs/1992Jairell.pdf ER - TY - Generic T1 - Snow fencing for water supplies T2 - 58th Annual Western Snow Conference Y1 - 1990 A1 - Jairell, R.L. A1 - Schmidt, R.A. KW - Snow fence, Water supply AB - Drought conditions during 1988-89 in southeastern Wyoming created opportunities to test several snow fence designs that capture snow as a water source for livestock, wildlife, and fisheries. Snow fence-embankment combinations that were most efficient in small-scale tests proved to be good choices to provide livestock water at several locations where deep wells went dry. Removal of upwind brush and installation of a metal apron in the accumulation area improved efficiency of a snow fence that supplied a guzzler for wildlife. Another snow fence accumulated enough additional water to prevent winter kill in a fishery. JF - 58th Annual Western Snow Conference T3 - Proceedings of the 58th Annual Western Snow Conference PB - Western Snow Conference CY - Sacramento, California UR - sites/westernsnowconference.org/PDFs/1990Jairell.pdf ER - TY - Generic T1 - Future directions of snow surveys and water supply forecasting in the Soil Conservation Service T2 - 58th Annual Western Snow Conference Y1 - 1990 A1 - Johnson, D.E. KW - Data collection, Interagency cooperation, Water resources, Water supply forecasting AB - This paper will cover five aspects of the future direction for Snow surveys and Water Supply Forecasting in the SCS:1. Increasing demands on water resources and needs for data,2. Data collection technologies,3. Water supply forecasting,4. Interagency cooperation, and5. Decision making for water resources. JF - 58th Annual Western Snow Conference T3 - Proceedings of the 58th Annual Western Snow Conference PB - Western Snow Conference CY - Sacramento, California UR - sites/westernsnowconference.org/PDFs/1990Johnson.pdf ER - TY - Generic T1 - Portable animal protection shelter and wind screen T2 - 56th Annual Western Snow Conference Y1 - 1988 A1 - Jairell, R.L. A1 - Schmidt, R.A. KW - Animal shelters, Blizzards, Snow drifts, Wind protection AB - Shelters formed by locking two steel corral panels in a 'V' pointing into the wind and covering them with reinforced plastic tarp or plastic snowfence provide temporary protection from wind and drifting snow. Developed primarily to aid stockmen by protecting problem animals during calving, these portable shelters also facilitate machinery repair or construction outdoors during blizzards or strong winds. Tests comparing porous (snowfence) and solid (tarp) coverings show greater wind protection with the porous cover, which also collects a snowdrift if blowing snow occurs. The solid tarp causes greater turbulence in the protected region, giving less wind protection, but no snow deposition occurred in tests during blizzards. Panels used in the tests were 5 ft high, 8 ft long, and weighed 105 lbs. Shelters were stable in gusts to 60 mph, when pointed into the wind. Anchoring is recommended if wind reversal is a possibility. JF - 56th Annual Western Snow Conference T3 - Proceedings of the 56th Annual Western Snow Conference PB - Western Snow Conference CY - Kalispell, Montana UR - sites/westernsnowconference.org/PDFs/1988Jairell.pdf ER - TY - Generic T1 - Scaling and constructing models for outdoor snowdrift tests T2 - 55th Annual Western Snow Conference Y1 - 1987 A1 - Jairell, R.L. KW - Blowing snow, Scale models, Snowdrifts AB - Reduced-scale models have proved a useful tool in predicting snowdrift patterns formed by structures and terrain features, solving practical engineering problems on an individual case basis. Successful modeling requires attention to dynamic conditions and to the model's proper scaling, their durability, and advanced preparation for modeling runs. This paper describes experience gained in 7 years of constructing these small-scale models that give consistant results in this dynamic environment. JF - 55th Annual Western Snow Conference T3 - Proceedings of the 55th Annual Western Snow Conference PB - Western Snow Conference CY - Vancouver, British Columbia UR - sites/westernsnowconference.org/PDFs/1987Jairell.pdf ER - TY - Generic T1 - Problems associated with the variability of southwest precipitation and seasonal snowpacks T2 - 54th Annual Western Snow Conference Y1 - 1986 A1 - Jones, R. A1 - Brazel, A.J. KW - Arizona, Median, Precipitation variability, Snowpack climatology AB - The effects of variability in the general climate of Arizona are considerable on snowpack conditions and resultant runoff from major watersheds of the region. The limited predictability of these conditions exacerbates problems of surface water management. Long term planning for surface water resources and analyses of seasonal snow conditions must be based on a reporting scheme that considers appropriate definitions of normals.The precipitaton regime and snowpack conditions of Arizona can be characterized as consisting of many dry years interspersed by extremes of wetness. This kind of regime lends itself to employing measures such as the median as a representation of the most frequent or normal condition. The current reporting of snowpack and precipitation relative to the mean or average long term condition may misrepresent the interpretation of an individual yearly pattern in the context of the long term expected snowpack and precipitation climate of the Southwest region. JF - 54th Annual Western Snow Conference T3 - Proceedings of the 54th Annual Western Snow Conference PB - Western Snow Conference CY - Phoenix, Arizona UR - sites/westernsnowconference.org/PDFs/1986Jones.pdf ER - TY - Generic T1 - Model studies of snowdrifts formed by livestock shelters and pond embankments T2 - 53rd Annual Western Snow Conference Y1 - 1985 A1 - Jairell, R.L. A1 - Tabler, R.D. KW - Blowing snow, Livestock shelters, Models, Snow fences, Snowdrifts AB - Although artificial barriers are commonly used to protect livestock from winter winds, the optimum design has yet to be determined for locations with blowing snow. This paper reports results from small-scale models studied outdoors under natural blowing snow conditions. Little snow accumulates initially on the lee side of solid shelters because blowing snow is entrained in the accelerated flow at the outer boundaries of the wake, and carried over or around the sheltered area. V-shaped and semicircular shelters form similar drifts and provide adequate protection if they are tall (3.7-5m), and have a diameter, or width, less than 15 times their height. A snow fence placed too close to the shelter increases deposition. Embankments should be confined to the downwind half of excavated stockwater ponds. A snow fence placed on top of an existing windward embankment will increase snow deposition within the pond. JF - 53rd Annual Western Snow Conference T3 - Proceedings of the 53rd Annual Western Snow Conference PB - Western Snow Conference CY - Boulder, Colorado UR - sites/westernsnowconference.org/PDFs/1985Jairell.pdf ER - TY - Generic T1 - The redistribution and sublimation loss of the snowpack in the alpine watershed T2 - 53rd Annual Western Snow Conference Y1 - 1985 A1 - James, E.D. A1 - Brendecke, C.M. KW - Modelling, Redistribution, Sublimation AB - A computer program was developed to estimate the redistribution and sublimation loss of the snowpack in the upper Green Lake Valley of the Boulder Watershed. The computer program is based on the the math models developed by R.A. Schmidt and Ronald Tabler on sublimation rate and redistribution of blowing snow. The program modifies the models to read daily weather data. The basin is broken into hydrologic response units (HRU), which are consistent to the segmentation of the Precipitation Runoff Modeling System (PRMS) used to model the runoff in the Boulder Watershed. The program computes how the snow is moved down the basin by the prevailing winds from one HRU to another and then computes average snow depth in each HRU for the winter months. The results are fed into the PRMS model prior to the start of the spring runoff. JF - 53rd Annual Western Snow Conference T3 - Proceedings of the 53rd Annual Western Snow Conference PB - Western Snow Conference CY - Boulder, Colorado UR - sites/westernsnowconference.org/PDFs/1985James.pdf ER - TY - Generic T1 - Portable ten-meter instrument mast T2 - 52nd Annual Western Snow Conference Y1 - 1984 A1 - Jairell, R.L. A1 - Tabler, R.D. A1 - Schmidt, R.A. KW - Instrument masts, Meteorological instruments, Wind profiles AB - This paper describes a portable 10-m mast for supporting vertical arrays of meteorological instruments. Constructed of aluminum and weighing 85 kg, the assembled mast with instruments attached can be moved by one person, and is easily adjusted to be verical over uneven or sloping surfaces. Complete fabrication drawings are provided. JF - 52nd Annual Western Snow Conference T3 - Proceedings of the 52nd Annual Western Snow Conference PB - Western Snow Conference CY - Sun Valley, Idaho UR - sites/westernsnowconference.org/PDFs/1984Jairell.pdf ER - TY - Generic T1 - Application of a snowmelt model to two drainage basins in Colorado T2 - 49th Annual Western Snow Conference Y1 - 1981 A1 - Jones, E.B. A1 - Shafer, B.A. A1 - Rango, A. A1 - Frick, D.M. KW - Landsat imagery, Runoff, Snowcovered area, Snowmelt runoff AB - The Martinec-Rango Snowmelt Model has evolved over a period of years from one that was developed for a relatively small drainage to its current application on much larger areas. The input requirements for the model include the remotely sensed percentage of snow-covered areas within the limits of the watershed, daily temperature, and precipitation. All of these data can be input on a multi-zonal basis.The current project analyzed the use of this model on the South Fork of the Rio Grande River (559 km sq) and on the Conejos River above Magote (730 km sq). Both of these watersheds are larger than had previously been considered for use with this model. The simulated volume of runoff versus the actual runoff were within 1 to 12 percent for the 6-month snowmelt period. Nash-Sutcliffe `R squared' values for daily runoff simulations exceeded 0.88 in all years except the very dry year of 1977. JF - 49th Annual Western Snow Conference T3 - Proceedings of the 49th Annual Western Snow Conference PB - Western Snow Conference CY - St. George, Utah UR - sites/westernsnowconference.org/PDFs/1981Jones.pdf ER - TY - Generic T1 - The avalanche warning program in Colorado T2 - 45th Annual Western Snow Conference Y1 - 1977 A1 - Judson, A. KW - Avalanche warning AB - Avalanche warnings for Colorado originate from the Forest Service's Rocky Mountain 'Forest and Range Experiment Station in Fort Collins. The current program, which began on an informal basis in 1962, has been operating formally as a joint venture with the National Weather Service since 1973. More than 150 avalanche warning bulletins have been issued during the past 3 winters. The warnings cover part or all of the State's high mountains west of the 105th meridian. Principle components of the warning system include a network of 55 mountain reporting sites, custom made mountain weather forecasts that feature predicted quantitative precipitation amounts from an orographic precipitation model, an avalanche warning center, and a communications system for disseminating avalanche warnings to the public. The program, now in its fourth winter, is running smoothly. Warnings have been well received by the public, and response has been good. Development of danger-rating models and fine tuning of the newly developed orographic precipitation model for the Colorado mountains will continue to aid the warning program. JF - 45th Annual Western Snow Conference T3 - Proceedings of the 45th Annual Western Snow Conference PB - Western Snow Conference CY - Albuquerque, New Mexico UR - sites/westernsnowconference.org/PDFs/1977Judson.pdf ER - TY - Generic T1 - Synoptic patterns associated with heavy spring snowfalls in southwestern Alberta T2 - 44th Annual Western Snow Conference Y1 - 1976 A1 - Janz, B. KW - Snow storm, Storm patterns AB - Several of the spring storms producing heavy precipitation in southern Alberta exhibit a remarkably similar synoptic pattern. The essential features common to these storms appear to be a moist southerly flow aloft over southern parts of the province coupled with a 'deep northeasterly upslope'.The topograghy of western Alberta is discussed in relation to its influence on spatial and time variations of heavy snowfall. JF - 44th Annual Western Snow Conference T3 - Proceedings of the 44th Annual Western Snow Conference PB - Western Snow Conference CY - Calgary, Alberta UR - sites/westernsnowconference.org/PDFs/1976Janz.pdf ER - TY - Generic T1 - Research coordination and utilization at Lake Tahoe T2 - 43rd Annual Western Snow Conference Y1 - 1975 A1 - Jones, J.R. KW - Research coordination, Research utilization, Watershed basin analysis AB - The Lake Tahoe Basin located in the Sierra Nevadas of California and Nevada is quite unique in that it brings together, many times in conflict, the snow, water, and people. With increased recreational demands and increased development, the spotlight has been on the Basin as the Tahoe Regioal Planning Agency has attempted to develop and enforce a General Plan which would allow planned growth and still adhere to environmental constraints. The Tahoe Regional Planning Agency and the Lake Tahoe Area Council, through funding from the National Science Foundation, have developed and are jointly administering the Research Coordination Unit. The primary objectives of this project are to identify research needs, coordinate research efforts, and make results readily available to governmental entities making planning and management decisions. The Lake Tahoe Area Research Coordination Board is comprised of a Governing Board and Science Advisory Panel, both with representation from various governmental, educational, and citizen oriented entities, and a small permanent staff. The benefits of this project are increased and more efficient utilization of research by government, the public, and the researchers. JF - 43rd Annual Western Snow Conference T3 - Proceedings of the 43rd Annual Western Snow Conference PB - Western Snow Conference CY - Coronado, California UR - sites/westernsnowconference.org/PDFs/1975Jones.pdf ER - TY - Generic T1 - Relative importance of weather factors creating slab avalanches in Colorado T2 - 32nd Annual Western Snow Conference Y1 - 1964 A1 - Judson, A. KW - Avalanches, Research AB - Slab avalanches experienced at Berthoud Pass, Colorado are described and classified into categories. Weather factors involved in the formation of slab avalanches are delineated. Avalanche information and causal factors are listed in tables together with text narration. Wind velocity and persistence during and after snowfall is shown to be the most important factor involved. JF - 32nd Annual Western Snow Conference T3 - Proceedings of the 32nd Annual Western Snow Conference PB - Western Snow Conference CY - Nelson, British Columbia UR - sites/westernsnowconference.org/PDFs/1964Judson.pdf ER - TY - Generic T1 - Benefits of forecasting date of low snow to water users of the Carson River T2 - 29th Annual Western Snow Conference Y1 - 1961 A1 - Johnson, W. KW - Critical flows, Water rights, Water supply forecasting AB - Problems of the cattle rancher using water for irrigation from un-regulated streams where water rights regulations necessitate the shutting off of the use when critical flows are reached. These shut-off dates are critical to crop development and harvest, and play an important part in the economy of the operations. Also the date of probable shut-off of primary and secondary water rights can be forecast within reasonable degree of accuracy is a step towards great economy in farming the semi-arid west areas. JF - 29th Annual Western Snow Conference T3 - Proceedings of the 29th Annual Western Snow Conference PB - Western Snow Conference CY - Spokane, Washington UR - sites/westernsnowconference.org/PDFs/1961Johnson.pdf ER - TY - Generic T1 - Use of the electronic computer for streamflow analysis T2 - 28th Annual Western Snow Conference Y1 - 1960 A1 - Johnson, L.F. KW - Electronic computer, Snow cover, Statistics, Water supply forecasting AB - A description of the processes used on the electronic computer for deriving multiple regression formulas using the many independent variables required in snow water supply forecasting is presented. The advantage of obtaining statistical relations between as many as 33 variables and streamflow figures within 15 minutes is shown. The detail results and procedures for developing a multiple regression formula for the Madison River at West Yellowstone, Montana with explanation of results, are given. Reasons for the 4 different forecast periods, together with peak flow and number of days to exceed critical flows are described. Four tables are included to show the results of the statistical criteria and formulas used. JF - 28th Annual Western Snow Conference T3 - Proceedings of the 28th Annual Western Snow Conference PB - Western Snow Conference CY - Santa Fe, New Mexico UR - sites/westernsnowconference.org/PDFs/1960Johnson.pdf ER - TY - Generic T1 - Snow hydrology summary report T2 - 24th Annual Western Snow Conference Y1 - 1956 A1 - Johnson, O. KW - Hydrology, Research programs AB - The Corps of Army Engineers, North Pacific Division, at Portland, Oregon, in cooperation with the U.S. Weather Bureau have produced a report of field studies completed by the Cooperative Snow Investigation program. These studies were conducted by the two agencies at three snow laboratories in differing climatic conditions in the Sierra Nevada, Cascade and Rocky Mountain areas. This report deals with the many problems involved in snow hydrology. The summary report consists of 12 chapters. Detailed text of the report includes tabulated data collected, graphs and formula development for solving complicated theories. An outline of the 12 chapters is included.Copies of this report are available from the Division Engineer, Corps of Army Engineers, Portland, Oregon. JF - 24th Annual Western Snow Conference T3 - Proceedings of the 24th Annual Western Snow Conference PB - Western Snow Conference CY - Penticton, British Columbia UR - sites/westernsnowconference.org/PDFs/1956Johnson.pdf ER - TY - Generic T1 - Estimating precipitation at San Francisco from concurrent meteorological variables T2 - 20th Annual Western Snow Conference Y1 - 1952 A1 - Jorgensen, D.L. KW - Evaluation of weather modification, Methods of weather modification, Weather modification AB - A study of meteorological factors responsible for producing rainfall is presented, and especially designed to develop a procedure for evaluating weather modification by the use of silver iodide generators. The main objective being to determine if rainfall would have occurred from a given set of atmospherical conditions without cloud seeding and if so, how much more was due to the artificial triggering. Upper-air masses at 400 and 700 mb. With open and closed low storm centers are plotted on scatter diagrams. Results are computed by probability theories and amounts of rainfall are snow. These data are compared to 12 and 24 hour amounts and monthly totals were computed by observed data.In discussion Dr. J. Neyman confines his remarks to the statistical probabilities and the procedures used in the paper and states that advance work will be forthcoming. JF - 20th Annual Western Snow Conference T3 - Proceedings of the 20th Annual Western Snow Conference PB - Western Snow Conference CY - Sacramento, California ER - TY - Generic T1 - Questionaire and answers on snow survey equipment and methods T2 - 4th Annual Western Interstate Snow Survey Conference Y1 - 1936 A1 - Jones, J.E. KW - Snow Survey questionnaire AB - By virtue of the relatively new science of snow surveying and water supply forecasting, the Western Interstate Snow Survey Conference sent a questionnaire to some 231 offices, engineers, and scientists involved in the study of streamflow from snow melt and related problems. Answers to (6) questions and comments were to be included. I.Field equipment; your preference as to type, style, and material and why. 16 items were listed. II. Snow survey courses; location, No./basin. No. points. III. Water supply forecasting; methods, procedures, justify. IV. Collateral data; variables used, length records. V. Streamflow data; normals, extension procedure, use. VI. Cost of snow surveys; per survey, transportation, equipment, observers, annual budgets. JF - 4th Annual Western Interstate Snow Survey Conference T3 - Proceedings of the 4th Annual Western Interstate Snow Survey Conference PB - American Geophysical Union, Transactions, Part II: CY - Pasadena, California ER - TY - Generic T1 - Improvements in snow-surveying apparatus T2 - 2nd Annual Western Interstate Snow Survey Conference Y1 - 1934 A1 - Jones, J.E. KW - Snow sampling equipment AB -

The Utah improvements on the Mt. Rose snow sampler by using duraluminum alloy tubing and a cheaper cutting bit and a tubular scale are described. All improvements were made for lightness, cheapness and back-packing facility. The use of the lighter tubing in constructing the sampler allows for a shorter tubular scale without sacrificing accuracy. Snow survey shelter cabins located strategically near the snow course is recommended for safety of the field parties.A discussion by S.P. Ferguson of Blue Hill Observatory relative to the original design of the Mt. rose sampling equipment is included and his recommendations for the new design of sampling tubes and scales now that duraluminum alloy tubing has become available in the correct sizes, and of equal strength.

JF - 2nd Annual Western Interstate Snow Survey Conference T3 - Proceedings of the 2nd Annual Western Interstate Snow Survey Conference PB - American Geophysical Union, Transactions 15: CY - Berkeley, California ER - TY - Generic T1 - Discussion of formal program T2 - 1st Annual Western Interstate Snow Survey Conference Y1 - 1933 A1 - Jones, J.E. KW - Snow survey problems AB -

Six problems dealing with streamflow forecasting from snow surveys and other factors involved in producing streamflow from snowmelt, are listed and discussed: 1) Can a series of streams be estimated according to a standard or must each be a problem by itself? 2) Would a master station be more desirable for giving scientific data to all agencies concerned? 3) What is the best method of determining the long time effects of dry year on runoff, soil capacity, etc.? 4) Has any method been devised for determining soil capacity for use in snow survey forecasting? 5) What is the effect of wind, temperature, rain, topography, porosity, and soil temperature on snowmelt runoff? 6) How much variation in time is permissible in consecutive years in making snow surveys to still get comparable results? These 6 points were suggested for future papers and discussion at forthcoming meetings.

JF - 1st Annual Western Interstate Snow Survey Conference T3 - Proceedings of the 1st Annual Western Interstate Snow Survey Conference PB - University of Nevada, Agricultural Experiment Station Bulletin CY - Reno, Nevada ER - TY - Generic T1 - Field equipment roundtable T2 - 1st Annual Western Interstate Snow Survey Conference Y1 - 1933 A1 - Jones, J.E. A1 - Lewis, G.A. A1 - Munson, S.M. A1 - Clyde, G.D. A1 - Herz, W.J. A1 - Herz, F. KW - Equipment, snow survey AB -

A round-table discussion is presented relative to the various pieces of equipment used in field snow surveying.George A. Lewis discussed the Mt. Rose Spring Balance, pointing out that excess friction and the lack of initial tension being insufficient for accurate results. He points out the convenience of having 6 ft. lengths of tubing cut into 3 ft. lengths and another coupling added. This facilitates carrying the tubes rather than the 5 ft. sections used in California. The cutters would have to have a harder temper as the ones now in use were bent too easily.Spencer Munson of California discussed the cutters used by that state as being hard enough. Also types of winter clothing was discussed including ski boots and equipment, and care of equipment during the off season.Discussion was had relative to shellac versus wax for snow tubes, to keep the snow from sticking to the bare metal. George Clyde described the Utah aluminum tubes and scales. Fred and Walter Herz discussed ski travel procedures.

JF - 1st Annual Western Interstate Snow Survey Conference T3 - Proceedings of the 1st Annual Western Interstate Snow Survey Conference PB - University of Nevada, Agricultural Experiment Station Bulletin CY - Reno, Nevada ER -